This invention relates to an apparatus for controlling the operation of a regenerative burner having a glow plug operable to ignite and burn a combustible mixture supplied into the burner so as to burn the exhaust particles collected in a trap located in the exhaust conduit of an internal combustion engine.
It has been proposed to purify exhaust gases from an automobile internal combustion engine by employing a trap located in the exhaust conduit of the engine to collect therein carbon or other particles included in the exhaust gases. The trap should be repetitively regenerated each time the amount of the exhaust particles collected in the trap reaches a limit value. For this purpose, a regenerative burner is provided upstream of the trap, the regenerative burner including a glow plug operable to ignite and burn a combustible mixture supplied into the burner so as to burn the exhaust particles collected in the trap when a regeneration requirement occurs.
With such a conventional trap regenerative device, however, the regenerative burner has a continuous supply of combustible mixture each time a regeneration requirement occurs even when the glow plug is subject to failure causing a failure to ignite the combustible mixture. The result is a large amount of unburnt fuel sticked on the exhaust system downstream of the regenerative burner, causing an increase in harmful exhaust emissions, exhaust system overheat, and trap burn-out.
Therefore, the present invention provides a regenerative burner control apparatus which can eliminate the difficulties attendant on conventional apparatus by control means operable to prevent the operation of the regenerative burner in the presence of a broken wire in the glow plug.